fn main() {
    let age:Result<u8, _> = "34".parse();
    if let Ok(age) = age {
        println!("The age is {}", age);
    } else if let Err(wrong) = age {
        println!("错误了{:?}", wrong);
    }
    let like_color:Option<&str> =  Some("green");
    if let Some(k) = like_color {
        println!("I like color is {}", k);
    } else {
        println!("there no color")
    }
}